$\dfrac{3}{100} + \dfrac{12}{10} = {?}$
Explanation: The fractions must have the same denominator before you can add them. Rewrite $\dfrac{12}{10}$ as $\dfrac{120}{100}$ $\dfrac{3}{100} + \dfrac{120}{100} = {?}$ $ = \dfrac{123}{100}$